is
class A
{
public virtual void F1() {
Console.WriteLine("A");
}
}
class B : A
{
public override void F1() {
Console.WriteLine("B");
}
}
class C
{
}
static void Main(string[] args)
{
A obj = new B();
if (obj is A)
{
Console.WriteLine("obj is A");
}
if (obj is B)
{
Console.WriteLine("obj is B");
}
if (obj is C)
{
Console.WriteLine("obj is C");
}
else {
Console.WriteLine("obj is not C");
}
Console.ReadKey();
}
obj is A
obj is B
obj is not C